Now with the continuous development of the chemical industry in China, the use of duplex stainless steel welded pipe is increasing. The global demand for duplex stainless steel pipes is growing rapidly every year, and there is also a good development in petroleum, urea and other industries.

The outstanding performance of duplex stainless steel pipes is mainly higher yield strength and better stress corrosion resistance, its welding performance is good, and the sensitivity of welding cold cracks and hot cracks is low.

Austenitic stainless steel welded pipes are mainly used in the decorative field, and relatively few corrosion-resistant welded pipes are used in the petrochemical field.

Chemical and petrochemical processing industry

The chemical industry is the area where duplex stainless steel is used earlier and more frequently. The catalyst tube of the medium and small methanol synthesis reactor uses duplex stainless steel, and the large and medium-sized device uses 2205 duplex stainless steel welded pipe.

Oil and gas industry

This is one of the main application aspects of duplex stainless steel. For the production of duplex stainless steel welded pipes for petroleum, the Chinese stainless steel pipe and fittings suppliers offer a good solution. It has done a good job in cost control, such as adopting new technologies and new processes, using molybdenum oxide balls instead of metal molybdenum, and nickel oxide instead of metal nickel, reducing smelting costs, popularizing the use of duplex stainless steel continuous casting technology, and increasing the yield.

Fertilizer Industry

The fertilizer industry mainly uses 0Cr25Ni6Mo3CuN aging-strengthened duplex stainless steel. Its wear and corrosion resistance is used for the internal parts of high-pressure shut-off valves of various specifications in the main process pipeline of the urea plant. The effect is still good.

The CO2 stripping method and NH3 stripping method for the production of urea mostly use high-alloy austenitic stainless steel, even titanium. The domestic has begun to use high-chromium duplex stainless steel instead of 316L on the carbamate pump body of the large-scale urea plant. (Urea grade) steel. Since the 1980s, the three high-pressure equipment of the stripping tower, the carbamate condenser and the high-pressure decomposition tower in the new ACES urea process developed by Japan’s Toyo Engineering Company have adopted DP-12 (25Cr-7Ni-3Mo containing trace tungsten and copper). -N steel) and R-5 (00Cr25Ni6.5Mo1.5N) duplex stainless steel. The former is used to make gas stripping pipes, condensers, decomposition pipes and conveying pipes, while the latter is used for high-pressure equipment shells.